SouthPark Player1 The one thing that stands out above all the others is that a classically trained pianist can play all the musical genres while those pianists which studied under another method cannot.
That touches on something important - to me, which is to never assume that a person cannot start in one area first, followed by expanding into another area. Objectives can be achieved in various or many ways.
Agreed. Also, the other thing that I think is important to mention is that all music requires training. So if someone is classically trained, they're not going to be able to just sit and start playing jazz piano without training in jazz piano.
I maybe said this above, in which case, forgive me for repeating myself.... but I do think there are a lot of contemporary solo piano styles for which classical training is sufficient. (Looking at you, Einaudi, Nevue, Ffrench...) But others (jazz, boogie woogie, blues, rock, playing from lead sheets...) will require training in that style.
It may be the case that someone who is classically trained will progress more quickly in those other styles, but the reverse is probably also true (a jazz pianist will progress with classical training)... but this is because the person already knows how to play the piano....
Anyway, I think I'm starting to repeat myself so I'll stop.